Speaking at a news conference, Johnston attacked Insurance Company of North America for declining, without a reason, to renew a group policy that expired June 30 for the homes. About 20 other insurers refused to quote a price for coverage, a local child-care official said.

Johnston, president of the Florida Senate, said this and similar troubles statewide are evidence of ''collusion'' among insurance companies in response to insurance reform passed by this year's Legislature.

Lawmakers rolled back insurance rates to January 1984 levels and gave the state insurance commissioner the authority to regulate commercial liability and property insurance rates.

''They're blackmailing us, trying to change the law immediately,'' said Johnston, a West Palm Beach Democrat who spoke earlier Friday to the bipartisan Bull Snort Forum in Orlando.

David Willis, a spokesman for Cigna, parent company of INA, which is based in Tampa, denied the charges.

''I categorically deny any collusion,'' he said from Cigna's home office in Philadelphia. ''In no way shape or form did we do that.''

He called the company's refusal to renew the $300,000 policy a business decision by the nation's largest writer of day-care insurance.

''There is a universal perception that the potential exposures to liability or risk at day-care centers are too unpredictable,'' Willis said.

The lack of insurance at the Orlando homes made them ineligible to receive state day-care subsidies for the poor, said Phoebe Carpenter of Community Coordinated Child Care, which helps indigent parents find child care.

Poor parents were forced either to pay for the services or move their children into day-care centers, which lack the family atmosphere, she said.

Mary Brown, who operates a day-care home, said she lost four children because of the loss of insurance. Her weekly income dropped from more than $300 to the $86 she gets for keeping two children who do not get subsidies, she said.

''I feel hurt and let down,'' Brown said.

Carpenter said she is continuing to look for an insurance company to write a policy.

Similar situations are occuring statewide, Johnston said. At one St. Petersburg day-care center, insurance rates rose 300 percent, he said.

The insurance company justified the increase because of the risk of child abuse, but the policy didn't cover child abuse, he said.

Johnston announced plans last month to ask Congress to repeal provisions of a federal law that exempts insurers from anti-trust laws.

He also said that as governor he would ask the Legislature to forbid any insurance compnay that pulls out of Florida from returning to the state for at least 10 years.

Other Democrats in the race for governor include former state Rep. Steve Pajcic of Jacksonville and Attorney General Jim Smith.